The field of invention is cigarette substitute nicotine inhaler tubes.
There are three patented concepts that define the field of invention regarding non-mechanical nicotine inhaler cigarette substitutes: U.S. Pat. No. 2,445,476 to Folkman; U.S. Pat. No. 6,769,436 to Horian and U.S. Pat. No. 5,400,808 to Turner, with continuations U.S. Pat. Nos. 5,501,236 and 6,098,632, all the foregoing Patents being incorporated herein by reference. These devices each define a self contained cigarette shaped open air tube inhaler designed to deliver evaporate to the user released from liquid nicotine contained within the tube.
It was Marvin L. Folkman (U.S. Pat. No. 2,445,476—1958) who may be first credited with the concept of a cigarette substitute meant to replace ignitable cigarettes by using liquid nicotine contained in a cigarette shaped tube and breathing air through the tube to deliver nicotine evaporate to the user. He first teaches an absorbent of tobacco or other material being placed inside an open air cigarette shaped tube then sealing the tube to prevent the escape of any vapors until used. The open air tube was to be capped with “plugs” to be removed by the user when ready for use.
Mr. Folkman's device might have been a practical and commercial success providing he would have been able to add the volatile liquid nicotine to the absorbent within the tube, ship and get the product to his customer within three days. However, the science and materials of his day would never allow his product to be adequately sealed to prevent the volatile liquid nicotine vapors from prematurely escaping within the tube to the open atmosphere before use.
If the tube is adequately sealed with a contiguous nicotine barrier material, the nicotine content can last for years. In effect, the sealed tube must be made of one continuous nicotine barrier material. However, without a hermetic seal, three days is all nature allows before the consumer will discover a tube container mostly depleted of vapor deliverables. Even today, with the advanced chemical resistant materials available, a plug or cap that will provide a friction or interference fit is not understood to exist. A hermetic seal requires a contiguous wall of barrier material. Any joint friction fit seal will fail. Only a fusion seal will contain the nicotine vapors, one where the material at the seal becomes seamlessly homogenous with the balance of the tubes chemical and pressure resistant material.
It was thought that there were only two ways to accomplish an appropriate seal. Turner teaches:                . . . a self-sealed, nicotine impermeable barrier enclosing the nicotine reservoir, said barrier including at least one nicotine barrier layer formed essentially of a copolymer effective in deterring nicotine migration; the barrier layer including at least two adjacent surfaces heat sealed to form a continuous nicotine impermeable barrier so that the nicotine can be prevented from migration outside the barrier.        
Simply, the Turner device has an open air tube with a “layer” meaning a second detached piece being sealed over the face of the opening at each end of the tube. This means that there must be a container of three or more pieces to be viable; the tube itself and the “layer” for each end of the open tube consisting of one or more layers included with the laminate being heat fused over the openings to accomplish closure and a “continuous nicotine impermeable barrier.”
The Horian patent taught the second way to accomplish a sealed liquid nicotine content tube that was a continuous nicotine impermeable barrier:                . . . an inhaler of volatile nicotine vapor, comprising a one piece tube pinch closed and sealed at the ends thereof, the one piece tube being impermeable to nicotine; a volatile nicotine contained within the tube; and an element in tube absorbent of the volatile nicotine.”The Horian device has a container consisting of only one piece as opposed to Turner's three or more piece container.        
In 2006, the Horian patent was challenged with an Inter-partes Reexamination at the United States Patent and Trademark Office. Over a period of four years, hundreds of pages of documents, including prior art patents from all over the world, were reviewed and carefully analyzed in the Reexamination. In the end, the Horian patent prevailed. It came down simply to the fact that there were only two ways to hermetically seal a nicotine content tube to become a continuous nicotine impermeable barrier. The prior technology either seals the open ends of the nicotine content tube with two or more layers of barrier material (Turner) or uses a one piece tube with pinch close heat fuse the ends (Horian).
It is important to understand why the tube sealing method and closures are so important when trying to construct a viable nicotine content, air flow inhaler. Liquid nicotine is the reason this task is so difficult to accomplish. Liquid nicotine, C10H14N2, is a colorless, poisonous alkaloid, derived from the tobacco plant and various vegetables such as eggplant, potatoes and tomatoes. It is the substance in tobacco to which smokers are understood to be addicted. The LD50 of nicotine is 50 mg/kg for rats and 3 mg/kg for mice. 40-60 mg can be a lethal dosage for adult human beings. This makes it an extremely deadly poison. It is more toxic than many other alkaloids such as cocaine, which has a lethal dose of 1000 mg. Nicotine is also a very tenacious substance. It will attack and or migrate through most plastic resins; even those usually designed for their chemical resistant properties. Nicotine has a vapor pressure of 0.53 MBR at 25 degrees C., surface Tension: 39.6 dyne/cm, Density: 1.032 g/cm3′ Flash Point: 101.7° C., and Enthalpy of Vaporization: 48.15 kJ/mol. Thus, not only is liquid nicotine a poison that can attack or migrate through many materials, it also has a vapor pressure that further complicates containment within any sealed tube to be used as a cigarette substitute intended for consumers to breath released volatile vapors.
With the difficulties of working with a nicotine content hermetically sealed container now understood, it is important to clarify precisely how the Turner and Horian patents are similar in use. Both the Turner and Horian containers are readied for use by severing or puncturing the exposed extreme ends of the container. Turner by puncturing the flat faced heat seal “barrier layer” and Horian by severing the extreme end of the pinched closed heat sealed ends.
Both methods leave the container portion that has been punctured or severed exposed to the mouth; more specifically the lips and tongue of the user. This can include jagged surfaces or burrs at the opening of the container which might cut or scratch the delicate skin surfaces of the user's mouth when contact with the container is made. Further, this places the interior of the tube immediately adjacent the mouth and tongue of the user, allowing contact with concentrated nicotine